In recent years, there is a strong demand for waterproof function in various electronic devices and accordingly, waterproof connectors having waterproof property have been under development for the purpose of use in connection with an external device.
One example of such waterproof connectors is a connector in which a housing made of insulating resin is formed to be integral with a conductive contact to contain the same therein by, for example, insert molding. Owing to the integral molding, a surface of the contact adheres at the portion embedded in the housing to the insulating resin making up the housing and this prevents water from entering the inside of the connector from the outside of the connector through a boundary portion between the housing and the contact.
In general, however, a metal material making up the contact and a resin material making up the housing are different in thermal expansion coefficient from each other and therefore, when the connector is exposed to a high temperature environment during a soldering process in mounting the connector onto a circuit board of an electronic device for example, owing to the different expansion amount between the contact and the insulating resin, the insulating resin adhering to the surface of the contact may be separated therefrom. Once the insulating resin is separated, a gap is generated between the surface of the contact and the insulating resin and water may disadvantageously enter the inside of the connector through the gap even after the temperature falls to ambient temperature.
Aside from that, when a counter connector is fitted to a connector in which a contact and a housing are formed integrally with each other, the counter connector may be forcibly fitted in a direction oblique to the fitting axis, which is so-called “ill fitting,” and a high stress may be applied to the portion between the housing and the contact. In this case, again, insulating resin making up the housing may be separated from a surface of the contact, which damages waterproof property of the connector.
To cope with it, for instance, Patent Literature 1 discloses a waterproof connector in which a tiny gap generated between a housing 1 and a contact 2 that are formed integrally with each other is filled with a waterproof sealant 3 to thereby improve waterproof property, as shown in FIG. 23.